Over the past few years, the long-standing idea that covalent modification of chromatin can
play a role in determining states of gene activity has been confirmed. Eukaryotic genes can
be silenced by deacetylation of acetyl-lysine moieties in the N-terminal tails of histones.
Recent work links histone deacetylases with an increasing number of repressors,
suggesting that deacetylation might be a rather pervasive feature of transcriptional
repression systems.